【作者】 武巴特尔；

【导师】 张天中；

【作者基本信息】 中国地震局地球物理研究所 ， 固体地球物理学， 2005， 硕士

【摘要】 本论文运用双差法开展了三方面的研究工作。 第一方面的工作是运用双差法对2004年8月—12月发生在南北地震带上的云南鲁甸地震序列进行了精确定位,同时在资料的处理和结果的分析上,建立了一整套比较完善的方法。具备了利用“南北地震带地震强化监测”项目的实时观测资料,对中等强度以上的地震序列进行精确定位的能力。从而可以给出更加准确的地震位置,为危险区划分及震情分析提供更加可靠的基础。 第二方面工作是通过理论分析、数值模拟试验、实际资料计算研究了近台资料对相对定位的影响。研究认为:双差法与主事件法、多重相对定位法以及震源矩心分解法不同,在速度变化较弱的地区它并不需要满足事件之间的距离远小于事件到台站距离这个条件。而且有近台资料时,由于台站离事件距离比较近,两个偏导数相差比较大,此时使用双差法有利于给出稳定的绝对位置和震源深度。 第三方面工作是依据双差法基本原理,采用Kennett和Engdahl(1991)研制开发的区域地震及远震理论走时计算的速度模型—IASPEI91地球模型,开发出了可以用于区域地震及远震的双差定位程序。并利用此程序对2003年新疆伽师地震序列进行了重定位,得到了比较好的结果。更多还原

【Abstract】 The double difference relative location approach (DD) is applied and investigated in this paper in the following three respects.Firstly, double difference method is used to relocate Ludian earthquake sequence occurring from August to December in 2004 and in Yunnan province located in the "north and south earthquake belt" (NSEB), and the more accuracy relative locations are obtained. We developed a set of methods in data processing and result analysis with the ability to use the real time data from temporary seismic network monitoring the NSEB and to relocate the moderate and strong earthquake sequence. The more accurate earthquake locations provide us basic information to analysis seismic activity and estimate the earthquake trend in NSEB.Secondly, the effect of data recorded at the nearby stations on DD algorithm is investigated in this paper by theoretical analysis, numerical modeling and actual data computation. The difference is found between DD and the master event technique, multiplet relative relocation as well as the hypocentroid decomposition (HDC), the condition that span between events is much less than the event-station distance is must be satisfied for latter but not for former when the velocity lateral heterogeneity is not so strong. The data recorded at nearby stations allow us to obtain the more accurate absolute earthquake position and depth estimation.Thirdly, a double difference relative location program using the regional earthquake and teleseismic data is developed, where theoretical travel time from event to station at regional and telseismic distances is calculated by IASPEI91 Earth model. The Jiashi earthquake sequence occurring in 2003 and Xinjiang province is relocated by the program, and the result seems more reasonable.更多还原